In the case of a prior art construction of such a quick change device the coupling members rigid with the housing comprise a coupling spindle on the working implement and engaging partially around this there are holding claws on the jib, the displaceably mounted coupling member being a spring loaded wedge which co-operates like a hook with the fixed coupling member disposed on the working implement, the wedge being capable of being locked outside the operative position by a locking device which is released during the process of coupling between jib and working implement so that for locking purposes the wedge becomes inserted under the hook due to the action of the spring; see AT-B 389 906.
It is also known for the displaceable coupling members to be constructed as locking bolts adapted for insertion via a lever arrangement into associated bores in a carrier plate on the working implement; see DE-A 17 84 323.
Finally, quick change devices are known in which the movable coupling members provided are spring loaded detents which,; in the coupling condition, engage over a matching bolt part and which are capable of being released by the application of an external force to oppose the spring force; see DE-A 33 12 442.
Common to all the previously known quick change devices are their complicated construction and susceptibility to breakdown, having regard to the severe conditions of use in earth moving work, so that the aim with such quick change devices, which is that the driver of the earth moving vehicle should be able to change over working implements without the help of further personnel, is unattainable.
On the other hand, however, there is a considerable need for easily operated quick change devices which function reliably for long working periods.
On a basis of the quick change device mentioned at the outset, the invention is based on the problem of providing a universally usable space-saving quick change device which, while having just a few component parts which in spite of the inevitable wear and tear will operate reliably over long periods, makes it possible for the driver alone securely to fit and interlock a working implement and jib on an earth moving machine.